135. Candy

There are N children standing in a line. Each child is assigned a rating value.
You are giving candies to these children subjected to the following requirements:
Each child must have at least one candy.
Children with a higher rating get more candies than their neighbors.
What is the minimum candies you must give?

正序遍历，大的+1，
逆序遍历，取最大的

c++版本：
class Solution {
public:
int candy(vector<int>& ratings) {
if(ratings.size()<=1)
return ratings.size();
vector<int> nums(ratings.size(),1);
for(int i=1;i<nums.size();i++)
if(ratings[i]>ratings[i-1])
nums[i]=nums[i-1]+1;
for(int i=nums.size()-1;i>=1;i--)
if(ratings[i-1]>ratings[i])
nums[i-1]=max(nums[i]+1,nums[i-1]);
int sum=0;
for(int num:nums)
sum+=num;
return sum;
}
};

python3版本：
class Solution:
def candy(self, ratings):
"""
:type ratings: List[int]
:rtype: int
"""
res=[1]*len(ratings)
lbase=rbase=1
for i in range(1,len(ratings)):
lbase=lbase+1 if ratings[i]>ratings[i-1] else 1
res[i]=lbase
for i in range(len(ratings)-2,-1,-1):
rbase=rbase+1 if ratings[i]>ratings[i+1] else 1
res[i]=max(res[i],rbase)
return sum(res)